Porcine peritoneal sepsis: modeling for clinical relevance.

The characteristics of two types of intraperitoneal (i.p.) soilage sepsis models, autologous fecal inoculum (FEC) and a pure culture of Escherichia coli (EC), were studied in 26 male Yucatan minipigs (20-30 kg). Early (1-4 h) and late (24-72 h) changes were different between the two groups. The EC group was characterized early by hypotension, low cardiac output, and increased systemic and pulmonary vascular resistances, along with leukopenia, hypoglycemia, lactacidemia, and elevated blood urea nitrogen. Of the pigs in the EC group that survived the early effects, there were few significant differences in physiological parameters, compared to control pigs, that would indicate ongoing pathological processes. In contrast, the FEC group pigs demonstrated early hypotension, but with increased cardiac output and reduced systemic vascular resistance. Other parameter changes were similar to those seen in the EC pigs, but to a lesser degree, with the exception of elevations in serum lactate dehydrogenase. Also in contrast to the EC group, most of the changes in the FEC group persisted in later days, and FEC pigs demonstrated leukocytosis. There were also greater elevations in circulating lipopolysaccharide (LPS) concentrations in the EC group that returned later to baseline levels. In the FEC group, there were persistently elevated LPS concentrations over 72 h. These observations suggest that pigs challenged with intraperitoneal E. coli demonstrated an initial acute peritonitis and damaging physiologic effects of high levels of circulating LPS. Survivors in this group improved and were physiologically stable after 24 h. Pigs that received i.p. autologous feces developed an early acute peritonitis phase with lower levels of circulating LPS, and later developed pronounced peritoneal reaction as demonstrated by multiple abdominal abscesses, pyogenic granuloma formation, and adhesions with physiological evidence of developing sepsis over 72 h. These observations indicate that i.p. EC models evoke a systemic response not unlike intravenous administration of LPS or EC, however, the FEC model produced a systemic response akin to a slower developing septic process.

Early detection of breast carcinoma: a comparison of palpable and nonpalpable lesions.

A retrospective study of 536 needle-localization biopsies of nonpalpable breast lesions and 623 excisional biopsies of palpable breast lesions was performed. Carcinoma was present in 17.9% of needle-localization biopsy specimens and in 11.1% of excisional biopsy specimens. Noninvasive carcinoma constituted 50% of carcinomas detected by needle-localization biopsy and only 7.3% of carcinomas detected by excisional biopsy (p less than 0.005). Invasive carcinoma detected by needle-localization biopsy was associated with axillary lymph node metastasis in 9.8% of patients who had axillary dissection, compared with 37.7% of patients with invasive carcinoma detected by excisional biopsy of a palpable mass (p less than 0.005). Invasive carcinoma detected by needle-localization biopsy was less than 2 cm in size (T1) in 93.5% of biopsy specimens; in contrast, invasive carcinoma detected by excisional biopsy was less than 2 cm in size in only 54.7% of biopsy specimens (p less than 0.005). Nonpalpable breast lesions that proved to be invasive carcinoma were pathologic stage I in 82.9% of patients. Palpable breast lesions that proved to be invasive carcinoma were pathologic stage I in only 47.2% of patients. Survival benefits of mammographic screening and biopsy of nonpalpable lesions are likely the result of detection of invasive carcinoma at an early stage and detection of noninvasive carcinoma that may later develop into or mark increased risk of invasive carcinoma.

Intestinal obstruction complicating pregnancy.

Intestinal obstruction is a rare but serious complication of pregnancy with significant maternal and fetal mortality. The reported incidence of intestinal obstruction complicating pregnancy varies widely, from 1 in 66,431 to 1 in 1,500 deliveries. A retrospective review of 66 cases of intestinal obstruction complicating pregnancy and the puerperium, including 2 cases from our institution, revealed that the most common causes of mechanical obstruction were adhesions (58%), volvulus (24%), and intussusception (5%). Seventy-seven percent of the patients with obstruction due to adhesions had undergone previous abdominal or pelvic surgery. Presenting symptoms and signs were similar to those of the nonpregnant patient; abdominal pain was present in 98% of patients, vomiting in 82%, and tenderness to palpation in 71%. In 82% of patients, obstruction was evident on radiographic evaluation. Prompt management of obstruction is essential; the median length of time from admission to laparotomy in the 66 patients was 48 hours. Bowel strangulation requiring resection was present in 23% of patients. Thirty-eight percent of patients completed term pregnancies after operative resolution of obstruction; total maternal mortality was 6%, and total fetal mortality 26%. Thus, both mother and fetus are at risk when intestinal obstruction complicates pregnancy. Clinical suspicion of the presence of obstruction and aggressive intervention are required to decrease the morbidity and mortality of this rare complication of pregnancy.

Radon-222 and progeny measurements in "typical" East Tennessee residences.

Modified Wrenn chambers for continuous monitoring of 222Rn, featuring several improvements including a computer-assisted electronics package, have been developed at the Oak Ridge National Laboratory. A field test of these instruments was conducted by placing them in the homes of staff members. Field testing was conducted in seven houses for periods ranging from 4 to 18 days. During this testing period, the 222Rn concentration in these houses was monitored continuously. Radon-222 concentrations in the basements of three of the seven houses were in excess of 100 Bq/m3 almost continuously. One residence had instantaneous concentrations approaching 1000 Bq/m3. Samples of soil and building materials from these residences indicated that 226Ra concentrations were in the normal range (40 Bq/kg). Radon progeny measurements were made in five of these houses on a "typical" day. Results obtained were as follows: for basements, a geometric mean of 0.016 WL (geometric S.D. of 2.9); for upper floors a geometric mean of 0.014 WL (geometric S.D. of 2.9). This paper summarizes the results obtained in the field test.

Computed tomography-guided needle localization of suspicious breast lesions.

Non-palpable breast lesions, suspicious for carcinoma, are usually localized prior to biopsy using standard mammographic techniques. We report two patients in whom computed tomography was used to localize suspicious non-palpable breast lesions that could not be readily localized using standard mammographic techniques.

The surgical significance of Persian Gulf sand.

Foreign bodies, in particular sand and soil particles, can cause considerable reaction in wounds and remain in tissues indefinitely. The introduction of foreign material as a contaminant in wounds and intracavitary injuries to military personnel deployed in the Persian Gulf region can be a complicating factor in treatment. Samples of desert sand from the military operational areas of the Persian Gulf were analyzed and the acute local and systemic responses of intraperitoneal contamination determined in an experimental rat model.

Stratification of palpable and nonpalpable breast cancer by method of detection and age.

BACKGROUND: Methods used to diagnose breast cancer in women under the age of 50 years are somewhat controversial. To determine the relationship between type and stage of breast cancer, clinical presentation, and age, we reviewed breast cancer diagnosed at our institution during a recent 3-year period. METHODS: Records from 589 consecutive excisional biopsies and 372 needle placement biopsies performed over a 3-year period were reviewed. Carcinomas were staged according to the TNM system and results compared using chi 2. RESULTS: Breast carcinoma was diagnosed in 118 women during the study period, 33% in patients under 50 years of age. Breast cancer diagnosed by mammography in all age groups was more likely to be noninvasive than that diagnosed by physical examination (p < 0.05). The few invasive cancers diagnosed by mammography in women under age 50 were lower in stage than those diagnosed by physical examination, although not by a statistically significant amount (p = 0.125). Breast cancer diagnosed by mammography in women 50 years and older was significantly lower in stage than that diagnosed by physical examination (p < 0.05). CONCLUSIONS: Invasive carcinoma detected as a nonpalpable lesion by mammography was earlier in stage than invasive carcinoma detected by physical examination, including in women under 50 years of age, although the number of invasive cancers detected in younger women was quite small. The role of mammography in this younger age group remains to be defined.

The use of local and systemic antibiotics in rat fecal peritonitis.

Treatment of fecal peritonitis includes administration of antibiotics, physical removal of contaminants, and restoration of gastrointestinal integrity. The temporal relationship of parenteral antibiotics and peritoneal irrigation with varied antibiotic solutions was studied in a peritonitis model. Antibiotics in high concentrations may actually inhibit host immune cells; therefore, dilute solutions used were MIC (minimum inhibitory concentration) (micrograms per millimeter) equivalent to usually achieved standard therapeutic blood levels. Sprague-Dawley rats were given a quantitative intraperitoneal challenge of 2 x 10(10) CFU/kg Escherichia coli and 10 mg autoclaved rat feces. Rats were randomized to receive 30 mg/kg intramuscular ceftriaxone (CTRX) either at the time of challenge (T = 0) or 2 hr later (T = 2). Two hours after peritonitis, rats received peritoneal irrigation with 30 cc of (1) normal saline, (2) dilute (10 mg/liter) CTRX solution, or (3) concentrated (1000 mg/liter) CTRX solution or (4) no irrigation. Survival and intraperitoneal pathology were then assessed. Parenteral CTRX given concurrently with peritoneal contamination improved survival (67%) compared with parenteral administration given 2 hr later (33%) (P < 0.05). Intraperitoneal CTRX irrigation improved survival (100%) in animals that received parenteral CTRX concurrently with contamination; this beneficial effect was present with both dilute and concentrated solutions and was significantly better than saline irrigation alone. Parenteral antibiotics given early after contamination of the peritoneum associated later with peritoneal lavage with antibiotic solutions improved survival.

"Renal dose" dopamine in surgical patients: dogma or science?

OBJECTIVE: "Renal dose" dopamine is widely used in the perioperative period to provide renal protection. A comprehensive review of the literature was performed to determine whether dopamine does in fact confer protection on the kidneys of surgical patients. SUMMARY BACKGROUND DATA: Studies in healthy animals and human volunteers reveal that dopamine causes diuresis and natriuresis, as well as some degree of renal vasodilatation. RESULTS: Studies of the perioperative use of dopamine fail to demonstrate any benefit of dopamine in preventing renal failure. Studies in congestive heart failure, critical illness, and sepsis also fail to show any benefit of dopamine other than diuresis. Further, dopamine administration is not completely without risk, because of dopamine's catecholamine and neuroendocrine functions. CONCLUSIONS: Routine use of prophylactic "renal dose" dopamine in surgical patients is not recommended.

Hypothermic coagulopathy in trauma: effect of varying levels of hypothermia on enzyme speed, platelet function, and fibrinolytic activity.

BACKGROUND: The coagulopathy noted in hypothermic trauma patients has been variously theorized to be caused by either enzyme inhibition, platelet alteration, or fibrinolytic processes, but no study has examined the possibility that all three processes may simultaneously contribute to coagulopathy, but are perhaps triggered at different levels of hypothermia. The purpose of this study was to determine whether, at clinically common levels of hypothermia (33.0-36.9 degrees C), there are specific temperature levels at which coagulopathic alterations are seen in each of these processes. METHODS: Of 232 consecutive adult trauma patients presenting to a Level I trauma center, 112 patients met the inclusion criteria of an Injury Severity Score of 9 or greater and time since injury of less than 2 hours. Of the included patients, 40 were normothermic and 72 were hypothermic (> or =37 degrees C, n = 40; 36.9-36 degrees C, n = 29; 35.9-35 degrees C, n = 20; 34.9-34 degrees C, n = 16; 33.9-33 degrees C, n = 7). Included patients were prospectively studied with thrombelastography adjusted to core body temperature. Additionally, PT, aPTT, platelets, CO2, hemoglobin, hematocrit, and Injury Severity Score were measured. RESULTS: Analysis by multivariate analysis of variance of the relationship between coagulation and temperature demonstrated that in hypothermic trauma patients, 34 degrees C was the critical point at which enzyme activity slowed significantly (p < 0.0001), and at which significant alteration in platelet activity was seen (p < 0.001). Fibrinolysis was not significantly affected at any of the measured temperatures (p > 0.25). CONCLUSIONS: Patients whose temperature was > or =34.0 degrees C actually demonstrated a significant hypercoagulability. Enzyme activity slowing and decreased platelet function individually contributed to hypothermic coagulopathy in patients with core temperatures below 34.0 degrees C. All the coagulation measures affected are part of the polymerization process of platelets and fibrin, and this process may be the mechanism by which the alteration in coagulation occurs.

Differences in mortality between elderly and younger adult trauma patients: geriatric status increases risk of delayed death.

BACKGROUND: Elderly patients suffer higher mortality rates after trauma than younger patients. This increased mortality is attributable to age, preexisting disease, and complications as well as injury severity. METHODS: Records from 5,139 adult patients from a Level I trauma center were retrospectively reviewed. Injury Severity Score (ISS), Revised Trauma Score (RTS), early mortality (<24 hours), and late mortality (>24 hours) were determined for elderly (> or =65 years) and younger (16-64 years) patients. Preexisting diseases and complications were identified by International Classification of Diseases, Ninth Revision, Clinical Modification diagnosis coding. RESULTS: Mortality in elderly patients was twice that in younger patients despite equivalent injury severity (p < 0.001), and elderly patients were more likely to suffer later death than younger patients (p < 0.005). The prevalence of preexisting disease was greater in the elderly, as was the incidence of complications. Using logistic regression, ISS, RTS, preexisting cardiovascular or liver disease, the development of cardiac, renal, or infectious complications, and geriatric status were all independently predictive of late mortality (p < 0.05). CONCLUSION: Elderly trauma patients more frequently suffer late mortality than younger patients because of the combination of injury and increased preexisting disease and complications after injury. Aggressive treatment of the elderly trauma patient is warranted; however, in the face of significant preexisting disease or complications, survival is less likely. Predictive models of survival can be developed, taking into account preexisting disease and complications as well as admission parameters such as age, ISS, and RTS, and specific risk of mortality quantitated.